bulk

1[singular]the bulk (of something)the main part of something; most of somethingThe bulk of the population lives in cities.

2[uncountable]the (large) size or quantity of somethingDespite its bulk and weight, the car is extremely fast.a bulk order(= one for a large number of similar items)bulk buying(= buying in large amounts, often at a reduced price)It's cheaper to buy in bulk.

3[singular]the weight or shape of someone or something largeShe heaved her bulk out of the chair.